Why is quantum theory being quantized

What is quantum physics?

The effects of quantum physics occur in the world of the smallest particles, at the atomic level and below. Only applications such as lasers, electron microscopy or superconductivity make quantum mechanical effects tangible in our world.

It is the case that measurements on very small particles, such as molecules or even smaller systems, often yield results that contradict classical physics. For example, it is the case that some quantities can no longer assume any arbitrary values, but only multiples of so-called “quantum values”.

Quantum mechanics The physicist Erwin Schrödinger was formative for quantum mechanics. Put simply, his approaches mean that physics is dependent, for example, on time and place. For example, it is not irrelevant WHO is sitting under an apple tree when it comes to the question of whether an apple falls on that person. This may seem strange to us, but it has been assumed in physics for over half a century.

He is best known for his thought experiment - "Schrödinger's Cat". Here one imagines that an unstable atomic nucleus, a cat and Geiger counter and a poison capsule are in a locked box. When the atomic nucleus disintegrates, radioactivity is released, which the Geiger counter measures, whereupon the deadly poison is released. This experiment is exciting because you cannot say whether the cat is still alive or already dead at a certain point in time. According to quantum theory, the atom is in a state of superposition, i.e. not yet decaying and already decaying. Accordingly, as long as the box is unopened, the cat should also be in this state - alive and dead at the same time.

Quantum physics brings into play ...

  1. Heisenberg's uncertainty principle: It is impossible to precisely determine the location and speed of a particle at the same time. Instead of electron orbits around atoms, orbitals are drawn, lounges for electrons in which they are likely to be located.
  2. Quantization: Some physical quantities such as energy or electrical charge can only occur in multiples of a smallest unit value.
  3. The prohibition of exclusion: elementary particles with the same quantum numbers that describe their state cannot be in the same place at the same time. But this does not apply to all elementary particles, which in turn leads to wonderful questions ...
  4. The entanglement: Two elementary particles that are "entangled" but are in two different places are "ghostly connected". If one observes one, the state of the other is immediately established. Quantum teleportation, quantum encryption and quantum computers are made possible with it.
  5. The difficult measurement: measurement is so disruptive that either quantum physical phenomena disappear completely, or the measurement influences the measurement so much that it is seriously changed.
  6. The wave-particle dualism: Not only is light a wave and a stream of particles (photons) in equal measure, but also matter. Electrons, protons and whatever are particles and waves at the same time. Some experiments show the particle character, others the wave character.

In the quantum world, you can walk through the wall, easily flow out of a glass, or do any other crooked thing. But be careful: everything is unfamiliar, we are not at home there!

Quantum physics was co-founded by three important attempts:

  1. The photoelectric effect: a charged metal plate can be discharged by irradiating it with light. Energy is transferred to the electrons, which can then leave the plate. However, only when the light is sufficiently energetic, with UV light. Imagine that the incoming light particles (photons) transport this energy.
  2. The problems with the blackbody. The amount of energy given off by a glowing object is mathematically infinite, which of course cannot be. The problem only became solvable with the quantization of the energy.
  3. The double slit experiment: electrons that fly towards a wall with two holes leave behind a pattern on a screen as if they were behaving as a wave. As soon as you want to find out which hole a certain electron has flown through, it behaves like in “classical mechanics”, the effect disappears. This strange behavior let Erwin Schrödinger formulate the thought experiment with "Schrödinger's cat".

The field of research in quantum physics becomes very complicated very quickly the deeper you go into it. Anyone who has mastered the field can express many phenomena in mathematical terms. If, however, an attempt is made to translate these connections into everyday language and thus into our everyday world, it is difficult to accept the strange phenomena or even to understand them approximately.

Young physicists developed quantum physics, people who were not very concerned about existing and established concepts: Niels Bohr, Albert Einstein, Max Planck and others.

An informative video on the subject (in English):

Video link to Alpha Centauri: What is the uncertainty relation?

Heisenberg's uncertainty principle is a kind of “holy grail” in physics - and at the same time extremely strange and complex. In it is the realization that one changes the observed world through the act of observation, so that one can never see it as it really is.

Video link to Alpha Centauri: Is Schrödinger's cat dead?

Still interested?

Interview with Anton Zeilinger, Viennese quantum physicist (Uni: View